Victorian plants may aid climate research

The scarcity of reliable long-term data on phenology – the study of natural climate-driven events such as the timing of trees coming into leaf or plants flowering each spring – have hindered scientists' understanding of how species respond to climate change.

But a team of ecologists have now found that plants pressed by collectors up to 150 years ago tell the same story about warmer springs resulting in earlier flowering as field-based observations of flowering made much more recently.

A total of 77 specimens of the early spider orchid (Ophrys sphegodes) collected between 1848 and 1958 were examined by the team from the Universities of Kent, East Anglia and Sussex and the Royal Botanic Gardens, Kew.

As each specimen contains details of when and where it was picked, the researchers were able to match this with Met Office records to examine how mean spring temperatures affected the orchids' flowering.

They then compared the data with field observations of peak flowering of the same orchid species in the Castle Hill National Reserve, East Sussex, from 1975 to 2006.

It was found that the response to flowering time to temperature was identical both in herbarium specimens and field data.

Ecologists say the results are the first direct proof that pressed plants in herbarium collections can be used to study relationships between phenology and climate change when field-based data is not available, which is commonly the case.

The study could open up important new uses for the 2.5 billion plant and animal specimens held in natural history collections in museums and herbaria.

It is hoped similar principles from the research, published in the British Ecological Society's Journal of Ecology, could be extended to museum collections of insects and animals.